One of the younger Hobbits who admired Bilbo and his stories; Fatty Bolger is another of Frodo's friends. He comes to help Frodo pack up Bag End, along with Folco Boffin, Merry Brandybuck, and Pippin Took. He is a part of Merry's conspiracy to help Frodo out on his quest.
Even though he loves Frodo dearly, Fatty's not one for adventures. So his co-conspirators decide that he should stay in the Shire rather than going off to Rivendell with everyone else. The plan is that Fatty will stay in Frodo's house in Crickhollow, occasionally wearing Frodo's clothes and generally making it seem as though Frodo is still living in Buckland. Sadly for poor Fatty, this plan backfires when the Black Riders turn up at the house at Crickhollow and break down the door, in the name of Mordor.
Fatty may not be very adventurous, but he’s not an idiot. When Fatty sees strange dark shadows at the front of the house, he goes running out the back door. Fatty collapses at a neighboring doorstep raving. His neighbors think that someone from the Old Forest is invading the Shire and start blowing the alarm horns. With the alarms blaring, the Black Riders ride quickly out of the Shire. So that’s something that Fatty achieves – getting the Black Riders out of the Shire.